The Sōbu Line (Rapid) (Japanese: 総武快速線, romanized: Sōbu-kaisoku-sen) is a railway service on the Sōbu Main Line in Tokyo and Chiba Prefecture, Japan, operated by East Japan Railway Company (JR East).

During weekday morning peak periods Tokyo-bound trains arrive once every 3.2 minutes; this is reduced to 10 Chiba-bound trains per hour during weekday evening peak periods.

Trains also travel through beyond Chiba to as far as: Before 16 March 2019, there were five Home Liner Chiba commuter liner services that operated every weekday evening, four of which started from Tokyo and another which started at Shinjuku.

Stations served: (Shinjuku – Akihabara) / Tokyo – Tsudanuma – Inage – Chiba Commuter Rapid services were abolished with the timetable revision on 12 March 2022.

[2] Prior to this they ran on weekday peak hours only, stopping at Tōkyō, Shin-Nihombashi, Bakurochō, Kinshichō, Funabashi, and Chiba.